Although the present invention is applicable to many different types of information provision, including advertising of products and services, providing order information and features for ordering products and services, providing information concerning events and opportunities, and provision of information of general or personal interest to intended recipients, the present invention is discussed, below, in the context of advertisements added to web pages displayed to users over the Internet, a context in which the present invention finds particular utility and applicability. When, for example, a web page describing a selected item is displayed to a user or customer who has requested information about that item, it may be possible to include in the web page references to additional items that may be of interest to the user. References may be descriptive material related to the additional items of interest, including images, summaries, and/or annotations, and may also be or include links to other web pages that describe the additional items of interest. Selecting and adding the references to the items may be an important marketing and advertising effort undertaken by an Internet retailer. Effective displays of items for purchase promote increased sales and revenues as well as additionally providing timely and useful information to browsers and purchasers of items from Internet-based shopping sites and catalogs, even when the users and customers do not immediately choose to purchase the items. Therefore, designers and vendors of web-page-based retailing sites and catalogs, Internet retailers, and, ultimately, customers of Internet retailers have all recognized that continued research and development efforts should be applied to advertising methods and systems.